Instruments For Expandable Interbody Implants

ABSTRACT

A system for implanting an expandable interbody implant into an intervertebral space includes an elongated tool, the distal end of which is removably securable to the implant. The proximal end of the tool has an attachment interface for detachable securement to a plurality of different modules, each of which is adapted to effectuate a different function of the delivery system. The different functions include: grasping the implant delivery tool, providing an impaction surface for driving the advancement of the implant, supplying a graft material into the implant, and actuating the expansion of the implant. One of the modules may include a fluid delivery system for supplying hydraulic fluid to expand the implant. A fluid reservoir of the fluid delivery system may be oriented transverse to the cannula that delivers the fluid to the implant. A grafting block can be used to help pre-pack the implant with graft material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/131,726 filed Sep. 14, 2018 which claims the benefit of the filingdate of U.S. Provisional Patent Application No. 62/559,037 filed Sep.15, 2017, the disclosures of which are hereby incorporated herein byreference.

BACKGROUND OF THE INVENTION

Intervertebral implants are commonly used in spinal surgery, such as ininterbody fusion procedures, in which an implant (e.g., a spacer orcage) is placed in the disc space between two vertebrae to be fusedtogether. At least a portion of the disc is typically removed before theimplant is positioned in the intervertebral space, and the implant maybe supplemented with bone graft material to promote fusion of thevertebrae. Interbody fusion procedures may also be performed inconjunction with other types of fixation, such as pedicle screwfixation, to provide additional stability, particularly while thevertebrae fuse together.

Different interbody fusion procedures can be distinguished by theirlocation along the spine (e.g., in the cervical, thoracic, or lumbarregions); by the type of implant used; and by the surgical approach tothe intervertebral space, in which different surgical approaches oftenimply different structural characteristics of the implant or implantsused. Different surgical approaches to the spine include anterior,posterior, and lateral. Examples of interbody fusion techniquesperformed along a posterior approach include posterior lumbar interbodyfusion (PLIF) and transforaminal lumbar interbody fusion (TLIF). PLIFtechniques typically include positioning two intervertebral implantsinto the intervertebral space along a posterior to anterior direction,with one implant being positioned towards the left side of the spine andone implant being positioned towards the right side of the spine. Theimplants used in such PLIF techniques typically have a straight shape,in that they extend along a central axis. TLIF techniques, by contrast,typically include positioning one intervertebral implant into theintervertebral space (often towards the anterior portion of theintervertebral space) from the posterior of the patient, but the spineis approached on one side from a more lateral position than in PLIFtechniques. The implants used in such TLIF techniques are often curved,such that they have an overall kidney bean-like shape. Interbody fusiontechniques performed along a lateral approach, on the other hand, ofteninvolve implants that are generally symmetric along their linearlongitudinal axis (e.g., having a substantially rectangular or ovalshape), but the implants are typically larger than those used in PLIF orTLIF techniques. That is, intervertebral implants used in lateralapproaches often cover a substantial portion of the disc space.

Included among the different types of intervertebral implants areexpandable implants. Such implants often have an initially contractedconfiguration, such that they have a low profile in thesuperior-inferior direction, in order to ease insertion into theintervertebral space. Such expandable implants can then be expanded inthe superior-inferior direction after implantation, so as to securelyengage and stabilize the vertebrae on both sides of the intervertebralspace. Examples of such expandable intervertebral implants are disclosedin U.S. Patent Application Publication No. 2017/0333199 (hereinafter“the '199 Publication”), U.S. Pat. No. 8,992,620 (hereinafter “the '620Patent”), and in U.S. Patent Application Publication No. 2017/0290671(hereinafter “the '671 Publication”), the disclosures of which arehereby incorporated by reference herein as if fully set forth herein.Expandable intervertebral implants having certain similar features tothose in the '620 Patent, the '199 Publication, and the '671 Publicationare disclosed herein, and therefore some similar nomenclature is usedherein for clarity and consistency.

Various tools that interface with the expandable implants for insertionand expansion are used. Although considerable effort has been devoted inthe art to optimization of such tools, still further improvement wouldbe desirable.

BRIEF SUMMARY OF THE INVENTION

Some aspects of the present invention provide a delivery system forimplantation of an implant into an intervertebral space. A deliverysystem in accordance with such aspects of the invention may include anelongated tool having a distal end removably securable to the implant. Aproximal end of the elongated tool may have an attachment interface fordetachable securement to a plurality of different modules. Each modulemay be adapted to effectuate a different function of the delivery systemduring implantation of the implant.

The different functions of the modules may include: grasping theelongated tool, providing an impaction surface for driving theadvancement of the implant, advancing a graft material through theelongated tool into the implant, and actuating the expansion of theimplant. For example, one of the modules may be a handle. At least oneof the modules may define a flat impaction surface at a proximal end ofa handle for driving the advancement of the elongated tool. That flatimpaction surface may be defined on a connect cap removably attachableto the handle. Another one of the modules may be a bone graft supplysystem. The bone graft supply system may include a plunger advanceablein a distal direction to drive graft material distally through theelongated tool and into the implant. The distal advancement of theplunger may be driven by squeezing a trigger of a pistol-grip handle.Another one of the modules may be an expander for actuating theexpansion of the implant. The expander may include a fluid deliverysystem for supplying hydraulic fluid into the implant to expand theimplant. The fluid delivery system may include a pressure gauge fordisplaying the pressure of the hydraulic fluid supplied to the implant.The fluid delivery system may include a plunger advanceable within afluid reservoir for driving the hydraulic fluid into the implant via afluid delivery cannula. The fluid reservoir may be oriented transverseto the fluid delivery cannula, such that the plunger is advanceablewithin the reservoir along a direction transverse to the fluid deliverycannula. The fluid delivery system may include a selector mechanism forswitching between two different modes of travel by the plunger. One ofthe two modes of travel by the plunger may include rotation of theplunger about its longitudinal axis, such that the plunger travels alonga threaded connection. Another one of the two modes of travel by theplunger may include sliding the plunger linearly along the longitudinalaxis of the plunger. The different modules may be securable to anddetachable from the proximal end of the elongated tool by depressing abutton on the respective module.

Other aspects of the invention provide a fluid delivery system forremovable connection to a hydraulically expandable intervertebralimplant. A fluid delivery system in accordance with such aspects of theinvention may include a fluid delivery cannula and a plunger having ahandle adapted to be grasped by a surgeon or other user. The handle mayinclude a gauge configured to display an indication correlated to thehydraulic pressure supplied to the intervertebral implant via the fluiddelivery cannula.

Yet other aspects of the invention provide a tool removably securable toan expandable intervertebral implant. A tool in accordance with suchaspects of the invention is configured for supplying a hydraulic fluidinto the implant to expand the implant. The tool preferably includes anelongated shaft having a fluid delivery cannula therein. The fluiddelivery cannula may have a distal end engageable with the implant suchthat the distal end is in fluid communication with a port on theimplant. At least the distal end of the fluid delivery cannula isdesirably a relatively rigid structure. The tool is preferably adaptedto induce movement of the fluid delivery cannula in a distal directionrelative to the shaft, such that the distal end of the fluid deliverycannula moves into engagement with a lock release within the implant soas to unlock the expansion of the implant and permit the implant tocollapse. In accordance with some aspects of the invention, the movementof the fluid delivery cannula in the distal direction relative to theshaft may be induced by a pivotable lever connected to the tool.

Other aspects of the invention provide an expandable intervertebralimplant. An implant in accordance with such aspects of the inventionpreferably include a housing and a top plate movable away from thehousing so as to expand the implant. The housing may include a sidesurface extending transverse to the top plate along a height dimensionof the implant. The side surface may have an opening therein, whichopening may communicate with an interior cavity of the implant so as topermit a graft material to be supplied into the interior cavity via theopening. The housing may also include a ramp extending between theopening and the interior cavity. The ramp is preferably oriented at anoblique angle to the side surface of the housing, so as to direct thegraft material to a particular location of the interior cavity along theheight dimension of the implant. A spinal implant system in accordancewith yet further aspects of the invention may include such an expandableintervertebral implant and may further include a reamer having aflexible shaft. The shaft of such reamer is preferably adapted to bereceived through the opening in the side surface of the implant andalong the ramp into the interior cavity of the implant. Desirably, suchreamer may be used to clear graft blockages during backfilling of theimplant.

Still other aspects of the invention provide a block for supporting anintervertebral implant while packing an interior cavity of the implantwith graft material. A block in accordance with such aspects of theinvention may include a base and a projection extending from the base.The projection is desirably sized to be received through a first openingin the implant such that the projection is positioned at least partiallywithin the interior cavity of the implant. A spinal implant system inaccordance with yet further aspects of the invention may include such ablock and may further include an intervertebral implant. Such implantdesirably includes a second opening on an opposite side of the implantfrom the first opening. When the implant is supported on the block withthe projection received through the first opening in the implant, thesecond opening is preferably oriented upwardly so as to receive a supplyof graft material into the interior cavity through the second opening.The projection of the block is desirably configured to closely fitwithin the interior cavity of the implant, such that graft materialpositioned within the interior cavity is prevented from flowingdownwardly past an upper surface of the projection into a portion of theinterior cavity occupied by the projection. In accordance with someaspects of the invention, the block may include a retaining mechanismconfigured to move into engagement with the implant to secure theimplant to the block.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an implant delivery system in accordancewith one embodiment of the present invention connected to an expandableimplant.

FIG. 2 is a perspective view of a delivery tool of the implant deliverysystem of FIG. 1.

FIG. 3 is a perspective view of a rotatable threaded member.

FIG. 4 is a perspective view of the insertion of the rotatable threadedmember into the delivery tool.

FIG. 5 is a perspective view of the rotatable threaded member insertedinto the delivery tool connected to an expandable implant.

FIG. 6 is a perspective view of a fluid delivery cannula.

FIG. 7A is a perspective view of the insertion of the fluid deliverycannula into the delivery tool.

FIG. 7B is a perspective view of the distal end of the delivery toolwith the fluid delivery cannula inserted and projecting distally towardsthe expandable implant.

FIG. 8 is a perspective view of the attachment of a connect cap forimpaction to the handle of the delivery tool.

FIG. 9 is a perspective view of the proximal end of the handle of thedelivery tool.

FIG. 10 is an exploded view of the connect cap of FIG. 8.

FIG. 11A is a perspective, cross-sectional view showing a sliding lockmechanism within the connect cap of FIG. 8.

FIG. 11B is a perspective view of the connect cap of FIG. 8 connected tothe proximal end of the handle of the delivery tool.

FIG. 12 is a perspective view of a different connect cap with a plungerfor the fluid delivery cannula.

FIG. 13 is a perspective view of the attachment of the connect cap andplunger of FIG. 12 to the handle of the delivery tool.

FIG. 14 is a perspective, cross-sectional view of the connect cap andplunger of FIG. 12 attached to the proximal end of the handle of thedelivery tool.

FIGS. 15A, 15C and 15D are top, cross-sectional views of the deliverytool connected to the expandable implant, showing the movement of thefluid delivery cannula by a flip lever of the delivery tool.

FIG. 15B is a perspective, cross-sectional view of the expandableimplant connected to the distal end of the delivery tool.

FIG. 16A is a perspective view of an alternative embodiment of a plungercontaining a pressure gauge for the fluid delivery cannula.

FIG. 16B is an exploded view of the plunger of FIG. 16A.

FIG. 16C is a cross-sectional view of the plunger of FIG. 16A.

FIG. 17 is a perspective view of a bone graft supply line.

FIG. 18 is a perspective view of the insertion of the bone graft supplyline into the delivery tool.

FIG. 19 is a perspective view of a plunger for the bone graft supplyline.

FIGS. 20A-20B are perspective views of the insertion of the plunger intothe bone graft supply line.

FIGS. 21A-21B are cross-sectional views of the movement of the plungerof FIG. 19 within the bone graft supply line.

FIGS. 22A-22B are perspective views of the attachment of a connect capfitted with a pistol-grip handle.

FIG. 23 is a perspective view of the insertion of a plunger that fitswithin the pistol-grip handle.

FIGS. 24A-24B are side, cross-sectional views of the pistol-grip handlewith the plunger inserted to deliver graft material to the expandableimplant.

FIG. 25 is a perspective view of a grafting block.

FIGS. 26A-26B are perspective views of the grafting block with theexpandable implant placed upon it and a retaining mechanism at varyingheights.

FIG. 26C is a perspective, cross sectional view of the grafting blockwith retaining mechanism having the expandable implant placed upon it.

FIG. 27 is a perspective view of the expandable implant on analternative embodiment of a grafting block without a retainingmechanism.

FIGS. 28A-28B are perspective, cross-sectional views of the expandableimplant on the grafting block of FIG. 27.

FIG. 29 is a perspective view of a graft reamer.

FIGS. 30A-30B are side, cross sectional views of the graft reamerinserted into the expandable implant.

FIG. 31A is a perspective view of the attachment to the handle of thedelivery tool of a connect cap with a fluid delivery plunger having twomodes of travel.

FIG. 31B is an exploded view of the connect cap of FIG. 31A.

FIG. 31C is a perspective view of a lever of a selector mechanism of theconnect cap of FIG. 31A.

FIG. 31D is a cross-sectional view of the selector mechanism of theconnect cap of FIG. 31A in an engaged position.

FIG. 31E is a cross-sectional view of the selector mechanism of theconnect cap of FIG. 31A in a disengaged position.

FIG. 32 is an exploded view of an implant delivery system in accordancewith another embodiment of the present invention.

FIG. 33A is a perspective view of the attachment of a handle of theimplant delivery system of FIG. 32 to an insertion shaft of the implantdelivery system.

FIG. 33B is a cross-sectional view of the arrangement of FIG. 33A.

FIG. 33C is an enlarged, cross-sectional view of the handle andinsertion shaft of FIGS. 33A-B connected to one another.

FIG. 34A is an exploded view of a delivery tool of the implant deliverysystem of FIG. 32.

FIG. 34B is a perspective view of the delivery tool of FIG. 34Aconnected to an expandable implant.

FIG. 35A is a perspective view of the delivery tool inserting andplacing the implant into the intervertebral space.

FIG. 35B is a perspective view of the arrangement of FIG. 35A, with thehandle removed from the insertion shaft of the delivery tool.

FIG. 36 is an exploded view of a fluid delivery system of the implantdelivery system of FIG. 32.

FIGS. 37A-37B are perspective views of the insertion of the fluiddelivery system of FIG. 36 into the delivery tool.

FIG. 38A-38B are cross-sectional views of the insertion of a plunger ofthe fluid delivery system of FIG. 36 into a reservoir of the fluiddelivery system.

FIG. 38C is a perspective, cross-sectional view of a plunger engagementmechanism engaging the plunger of the fluid delivery system of FIG. 36.

FIGS. 39A-39B are perspective views of the insertion shaft of theimplant delivery system of FIG. 32 connected to the expanded implantwithin the intervertebral space.

FIGS. 40A-40B are perspective views of the insertion of a bone graftsupply line into a bone graft supply system of the implant deliverysystem of FIG. 32.

FIGS. 41A-41B are perspective, cross-sectional views of the bone graftsupply line connected to the bone graft supply system of FIGS. 40A-B.

FIGS. 42A-42B are perspective views of the insertion of a bone graftsupply system into the implant delivery system of FIG. 32.

FIG. 42C is a perspective view of the bone graft supply system of FIGS.42A-B injecting bone graft material into the implant.

FIG. 43 is a simplified view showing a delivery tool in accordance withanother embodiment of the present invention inserting an implant into anintervertebral space along a lateral approach.

FIG. 44 is a perspective view of a delivery tool in accordance withanother embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates an embodiment of an implant delivery system forinsertion of an expandable implant 10 into an intervertebral space inaccordance with the present invention. The expandable implant 10 may,for example, be structured like any of the embodiments of expandableimplants disclosed in the '199 Publication. A delivery tool 100 of thedelivery system is comprised of a handle 550 connected to an insertionshaft 500. The handle 550 is adapted to be grasped by a surgeon or otheruser while the expandable implant 10 is inserted into the intervertebralspace using the delivery tool 100, and the handle 550 includes featuresat its proximal end to facilitate engagement with, and control of, theexpandable implant 10. The expandable implant 10 is connectable to thedistal end of the insertion shaft 500. Various connect caps of thedelivery system can be fitted to the proximal end of the handle 550 viaa connection mechanism that allows for connect caps to be interchanged.Each connect cap serves a different purpose during implantation of theexpandable implant 10 and can be readily switched without disconnectingthe delivery tool 100 from the implant 10 and without removing theimplant 10 from the intervertebral space.

Connect cap 502 allows for the advancement of plunger 506 for the fluiddelivery system and plunger 508 for the bone graft supply line 404.Connect cap 504 provides for a durable impaction surface duringinsertion of the expandable implant 10. Both connect cap 502 and connectcap 504 have a button 503 that facilitates the attachment and removal ofconnect caps 502 and 504. The delivery tool 100 also has a flip lever510 that allows for unlocking and collapsing the expandable implant 10.

FIGS. 2-5 illustrate the insertion of rotatable threaded member 158.FIG. 2 illustrates the delivery tool 100 having a receptacle 512 forreceiving a rotatable threaded member 158, a receptacle 514 for thefluid delivery cannula 154, and a receptacle 516 for the bone graftsupply line 404. The receptacle 512 for receiving the rotatable threadedmember 158 extends from the proximal end of the handle 500 through thedistal end of the insertion shaft 500. The distal end of the rotatablethreaded member 158, as illustrated in FIG. 3, is inserted into theproximal end of receptacle 512, as illustrated in FIG. 4. The distal endof the rotatable threaded member 158 extends out of the distal end ofthe insertion shaft 500 and connects with the proximal end of theexpandable implant 10, as illustrated in FIG. 5, in order to secure theimplant 10 to the delivery tool 100. Specifically, the expandableimplant 10 is secured to the delivery tool 100 by threading the threadeddistal end of the rotatable threaded member 158 into a delivery toolanchor in the form of a threaded receptacle on the proximal end of theexpandable implant 10, as disclosed in the '199 Publication. Whenconnecting the rotatable threaded member 158 to the expandable implant10, connect cap 502 or 504 need not be attached to the handle 550 of thedelivery tool 100.

Receptacle 514 is for receiving the fluid delivery cannula 154 of afluid delivery system. The fluid delivery cannula 154 allows forhydraulic fluid to be delivered to expandable implant 10 to expandexpandable implant 10. Beneficially, by receiving the hydraulic fluiddelivery components within the handle 550 and insertion shaft 500 (e.g.,in receptacle 514), the delivery tool 100 may be easier to manipulatethan some delivery tools, which may include bulky external syringes forsupplying hydraulic fluid.

As illustrated in FIG. 6, fluid delivery cannula 154 includes areservoir 518 at the proximal end of the fluid delivery cannula 154 andan outlet 152 for delivering pressurized fluid at the distal end of thefluid delivery cannula 154. The reservoir 518 has a rack mechanism 520along its periphery that will interact with a pinion mechanism 522 atone end of flip lever 510, as shown in FIG. 15C (and discussed below).Outlet 152 for delivering pressurized fluid is inserted into receptacle514 for the fluid delivery cannula at the proximal end of the handle550, as illustrated in FIG. 7A. After the fluid delivery cannula 154 isseated in the handle 550 and insertion shaft 500, the outlet 152 fordelivering pressurized fluid will be located at the distal end of theinsertion shaft 500, where it can fluidly communicate with the inlet ofa pressure channel on the proximal end of the expandable implant 10. Asshown in FIGS. 15A and 7B, the outlet 152 may project from the distalend of the insertion shaft 500, such that it is partially receivedwithin the inlet of the expandable implant, where it can form a sealingconnection by engaging an o-ring positioned within the pressure channelof the implant 10, as disclosed in the '199 Publication.

FIGS. 8-11B illustrate how connect cap 504 attaches to the proximal endof handle 550 of delivery tool 100. Preparation for attachment ofconnect cap 504 to handle 550 is illustrated in FIG. 8. Connect cap 504provides for a flat surface on its proximal end to provide a durableimpaction surface to help insert or place expandable implant 10.

Connect cap 504 can be interchanged with connect cap 502 and connect cap702 at various points during the use of the delivery tool 100. Connectcap 502 provides for plunger 506 and plunger 508 to be used inconjunction with the delivery tool 100. Connect cap 702 provides apistol-grip handle 700 that can be used to back-fill interior cavity 15of expandable implant 10 with graft material.

FIG. 9 illustrates an attachment interface 528 at the proximal end ofthe handle 550 to which the connect cap 504 will be attached. Theattachment interface 528 includes two recesses 511 to allow foralignment between handle 550 and connect cap 504, by receivingcorresponding projections 505 of the connect cap 504, as discussedbelow. The attachment interface 528 also includes a locking mechanism534 for keeping the connect cap 504 securely attached to the attachmentinterface 528. The locking mechanism 534 includes a projection 501having a recess 532 and one or more (e.g., two) overhead projections530. Although not illustrated in the other figures, the proximal end ofthe handle 550 may also include a connection 536 (e.g., a threaded bore)for securely and removably connecting to a slap hammer to assist withremoval of the delivery tool 100 and implant 10 in the proximaldirection if the implant 10 becomes stuck in the intervertebral space.

As illustrated in FIG. 10, connect cap 504 is comprised of a slidinglock mechanism 535 having a central hole 537 in it that is shaped toreceive the projection 501 on the proximal end of handle 550. Thesliding lock mechanism 535 is spring-biased, using springs 507. A stoppin 509 is received through a slot 542 in the sliding lock mechanism 535to constrain the travel of the sliding lock mechanism 535, such that thesliding lock mechanism 535 is retained within the connect cap 504. Thesliding lock mechanism 535 includes an outwardly projecting button 503,which may be a projecting portion of the sliding lock mechanism 535projecting out of slot 539 on connect cap 504.

The sliding lock mechanism 535 allows for connect cap 504 to be lockedto the locking mechanism 534 of the handle 550. Specifically, whenconnect cap 504 is being attached to the proximal end of handle 550, asillustrated in FIGS. 11A-11B, button 503 is pressed, causing springs 507to compress, so that the central hole 537 becomes aligned withprojection 501. Projections 505 on the distal end of connect cap 504align with recesses 511 on the proximal end of handle 550. Once connectcap 504 is aligned and seated on the attachment interface 528 at theproximal end of handle 550, button 503 is released, causing springs 507to de-compress and lock the locking mechanism 534 into place.Specifically, when the button 503 is released, the sliding lockmechanism 535 slides such that stop pin 509 slides within slot 542, theend 540 of central opening 537 slides into the recess 532 of projection501, and the side peripheral edges 544 of the sliding lock mechanism 535slide under the overhead projections 530. The inter-engagement of allthose structures discussed above prevents the connect cap 504 frombecoming disconnected from handle 550 when the button 503 is in itsundepressed position.

Removal of connect cap 504 is done through a similar process asattaching connect cap 504. That is, to remove connect cap 504, button503 is pressed, causing springs 507 to compress. This shifts slidinglock mechanism 535 such that it is no longer locked into place by theoverhead projections 530 on projection 501 or by the recess 532 inprojection 501. Once button 503 is pressed, connect cap 504 can belifted off handle 550.

The connect cap 502 may have substantially the same attachment structureas the connect cap 504, and therefore attaching and removing connect cap502 may use the same process as connect cap 504, as described above.

The structure of connect cap 502 allows for either or both of plunger506 or plunger 508 to be received through or removed from the connectcap 502 during the use of the delivery tool 100. There are multiplereceptacles in the connect cap 502. Receptacle 524 is threaded toreceive the plunger 506 of the fluid delivery system, which is used topush the hydraulic fluid into the expandable implant 10. Receptacle 526receives plunger 508 that is used to push graft material in order toback-fill the expandable implant 10 after it has been expanded.

The distal end of plunger 506 is inserted into receptacle 524 on connectcap 502, as seen in FIG. 12. Receptacle 524 is threaded to match thethreading of plunger 506. FIG. 13 illustrates how connect cap 502 can beattached to the proximal end of the handle 550 of the delivery tool 100after having already received plunger 506.

FIG. 14 illustrates how connect cap 502 with plunger 506 align andfunction with all the other elements of handle 550. Plunger 506 isseated within reservoir 518. Threadedly advancing the plunger 506 pushesthe hydraulic fluid through fluid delivery cannula 154 and out theoutlet 152, which is in fluid communication with the inlet of a pressurechannel of the expandable implant 10.

Plunger 506 for the fluid delivery cannula 154 has a structure on theproximal end that allows for a variety of handles to be attached forturning plunger 506. FIGS. 16A-16C are exemplary of the shape of whatthe handle may look like. FIGS. 16A-16C illustrate the handle 602 with apressure gauge 600 embedded in the handle. Another embodiment of handle602 may be without such a recess or a pressure gauge embedded within it.

Plunger 506 can be operated by turning an attached handle. As the handleis turned, plunger 506 pushes hydraulic fluid from reservoir 518 throughthe fluid delivery cannula 154 and out the outlet 152 into theexpandable implant 10 causing expandable implant 10 to expand.

In an alternative embodiment, as illustrated in FIGS. 31A-31E, connectcap 502 may be replaced with connect cap 1002, which includes a selectormechanism 1004 for selecting between two modes of travel by the plunger1006 that pushes the hydraulic fluid into the implant 10. In one mode,the plunger 1006 may be threadedly engaged within a receptacle 1024 inthe connect cap 1002 so that the plunger 1006 can travel (i.e., beadvanced or retracted) by rotation about its longitudinal axis, similarto plunger 506. In another mode, the threads may be disengaged from theplunger 1006 so that the plunger can travel by sliding it linearlythrough the receptacle 1024. The process of attaching and removingconnect cap 1002 is the same process as attaching and removing connectcaps 502 and 504. That is, the connect cap 1002 may have a sliding lockmechanism 1035 constrained by a stop pin 1009 in the same manner as thesliding lock mechanism 535 and stop pin 509 of connect caps 502 and 504.

The selector mechanism 1004 for selecting between the two modes oftravel may include a pivotable lever 1008 controllable by manipulatingan external projection 1010 such that the lever 1008 pivots about apivot pin 1012 received through a hole 1014 in the lever 1008. Suchpivoting of the lever 1008 may selectively bring threads 1016 on thelever 1008 into engagement with threads on the plunger 1006, as shown inFIG. 31D, or it may disengage the threads 1016 of the lever 1008 fromthe threads of the plunger 1006, as shown in FIG. 31E. The lever 1008can be held in the engaged and disengaged positions by a pin 1018 thatengages respective notches 1020 and 1022 formed on the lever 1008. Thus,by pressing on the projection 1010 when the lever 1008 is in the engagedposition shown in FIG. 31D (in which the pin 1018 is received by notch1020), the lever 1008 can be pivoted about the pivot pin 1012 to thedisengaged position shown in FIG. 31E. The lever 1008 can then be heldin that disengaged position, in which the threads 1016 are spaced apartfrom the plunger 1006, by having the pin 1018 positioned in notch 1022.A biasing spring 1025 may bias the lever 1008 back towards the engagedposition. Thus, the lever 1008 may be returned to the engaged positionof FIG. 31D by pushing distally on a button 1026 connected to the pin1018, so that the pin 1018 compresses a spring 1028 until a narrowedregion 1030 of the pin 1018 becomes aligned with the notch 1022, thusallowing the lever 1008 to rotate back towards the engaged positionunder the influence of the biasing spring 1025. Alternatively, the lever1008 may be moved back to the engaged position by simply pulling on theprojection 1010 until the pin 1018 disengages the notch 1022.

The two modes of travel discussed above may desirably permit the plunger1006 to advance the hydraulic fluid into the implant in the rotational,threaded engagement mode, and then the plunger 1006 can be quicklyreleased by disengaging the lever 1008 and pulling the plunger 1006 inthe proximal direction. The two states of engagement between the lever1008 and the plunger 1006 may also give the surgeon a choice between twomodes for delivery of the hydraulic fluid into the implant. That is, thesurgeon may use the threaded advancement mode if a slower and morecontrolled advancement is appropriate, and/or if it is desirable toemploy the mechanical advantage provided by the screw drive to amplifythe input force. The surgeon may also choose to use the sliding,non-threaded mode if more rapid advancement of the plunger is desirable.The sliding, non-threaded mode may also desirably allow the plunger 1006to be initially positioned into or removed from the receptacle 1024 ofthe connect cap 1002 relatively quickly, by eliminating the need tothreadedly advance or retract the plunger 1006 the entire distance tothe desired position.

FIGS. 15A-15D illustrate the interaction between rack mechanism 520 onreservoir 518 and pinion mechanism 522 on flip lever 510. Before fliplever 510 is activated, outlet 152 for delivering pressurized fluid atthe distal end of the fluid delivery cannula 154 is a distance away fromthe pushable unlocking tether 212 a in the expandable implant 10, asillustrated in FIGS. 15A-B. As disclosed in the '199 Publication,pressing distally on the pushable unlocking tether 212 a allows forexpandable implant 10 to collapse so that it can be repositioned ifnecessary. That is, the expandable implant 10 may include a pushableunlocking tether 212 a engaged with a lower lock support so as to rotatethe lower lock support 20 in the unlock direction when the pushableunlocking tether 212 a is pushed in the distal direction.

FIG. 15C illustrates the activation of flip lever 510. As the flip lever510 is pivoted outwardly from its initial position extending along andsubstantially flush with the outer surface of the handle 550 as shown inFIGS. 13-14, the pinion mechanism 522 on the flip lever 510 interactswith rack mechanism 520 on reservoir 518 to cause reservoir 518 andfluid delivery cannula 154 to move towards the distal end of insertionshaft 500. As reservoir 518 and fluid delivery cannula 154 move towardsthe distal end of insertion shaft 500, outlet 152 for deliveringpressurized fluid also moves distally and pushes on the internalunlocking mechanism within the expandable implant 10, as shown in FIG.15D. This causes the expandable implant 10 to collapse so that theexpandable implant 10 can be repositioned if necessary. Returning fliplever 510 to the original position withdraws outlet 152, fluid deliverycannula 154, and reservoir 518 back to the original depth, allowingexpandable implant 10 to be re-expanded.

Instead of using a thin, flexible wire to push the unlocking mechanismwithin the expandable implant 10, as may be done in some other deliverytools, the flip lever 510 may beneficially allow for the relativelyrigid structure of fluid delivery cannula 154 to move to activate theunlocking mechanism within expandable implant 10.

In another embodiment of delivery tool 100, FIGS. 16A-16C exemplifyhandle 602 having a pressure gauge 600 to measure the pressure of thefluid in the fluid delivery cannula 154 as the handle 602 is turned.Pressure gauge 600 provides numerical readings of the pressure of thefluid inside the expandable implant 10. Handle 602 has a recess toreceive pressure gauge 600. The distal end of pressure gauge 600 has athreaded member that allows for a secure connection between pressuregauge 600 and handle 602.

The distal end of handle 602 is threaded to receive the threadedproximal end of handle connector 610. A secure connection between handle602 and handle connector 610 is formed such that the rotation of handle602 is transmitted to the handle connector 610. Handle connector 610connects handle 602 to plunger 606. The proximal end of plunger 606 isfitted to have o-ring 608 as part of its assembly when connected to thedistal end of handle connector 610.

Plunger 606 has a passageway 612 to provide fluid communication betweenthe fluid delivery cannula 154 and the pressure gauge 600, so that thepressure gauge 600 can read the pressure in the fluid delivery cannula154 as hydraulic fluid is delivered to the expandable implant 10. Thepassageway 612 in plunger 606 communicates with passageways in handle602 and handle connector 610, as shown in FIG. 16C. O-ring 608 is inplace to create a seal between the plunger 606 and handle connector 610to minimize leakage between those components. Plunger 606 also has ano-ring 604 located at the distal end of plunger 606 that creates amovable seal between the plunger 606 and the reservoir 518 of the fluiddelivery cannula 154 as the plunger 606 advances within the reservoir518.

The distal end of plunger 606 is inserted into the proximal end ofreceptacle 524 on connect cap 502. The threading of plunger 606 is thesame as plunger 506, allowing the threading of plunger 606 to also matchthe threading of receptacle.

Plunger 606 is operated by turning handle 602. As the handle 602 isturned, plunger 606 pushes hydraulic fluid from reservoir 518 throughthe fluid delivery cannula 154 and out the outlet 152 into theexpandable implant 10, causing expandable implant 10 to expand.Beneficially, the pressure gauge 600 may provide an absolute reading,instead of a relative measure, of the pressure of the fluid in theexpandable implant 10. This may help prevent the surgeon fromover-pressurizing the expandable implant 10. In an alternativeembodiment, the gauge may provide a relative pressure reading, such asby displaying color-coded regions associated with different pre-definedranges of pressure.

The delivery system provides a bone graft supply system for back-fillingthe expandable implant 10 with graft material. The bone graft supplyline 404 of the bone graft supply system, as illustrated in FIG. 17, isa cannula that does not have to be inserted into the delivery tool 100until after the expandable implant 10 is inserted. By inserting the bonegraft supply line 404 into the delivery tool 100 after the expandableimplant 10 is inserted, there will be better visualization of theanatomy and the expandable implant 10 during insertion and graftmaterial can be prepared and loaded at the same time the expandableimplant 10 is being inserted. The cannula used for the bone graft supplyline 404 may also be translucent, which allows for better visualizationof the amount of graft material being delivered.

In some embodiments it may be preferable to have a large diameter bonegraft supply line 404 for receiving different sizes of graft material.In one embodiment, the diameter of the bone graft supply line 404 is 6mm ID. In contrast to other commercial products, providing such a largerdiameter bone graft supply line 404 may beneficially allow for the useof more types of graft materials, such as cancellous chips, autograft,or synthetic bone graft materials such as those manufactured byOrthovita, Inc. under the trademark VITOSS®.

As illustrated in FIG. 18, the distal end of the bone graft supply line404 is inserted into the proximal end of receptacle 516 on the handle550. Once bone graft supply line 404 is seated within receptacle 516 inhandle 550, a plunger 508 of the bone graft supply system is introducedand inserted into the proximal end of the bone graft supply line 404, asillustrated in FIGS. 19-20B, for dispensing the graft material. AlthoughFIG. 20 does not illustrate connect cap 502 being connected to handle500, it may be in place when using plunger 508, in which case theplunger 508 can be introduced through the receptacle 526 of the connectcap when inserting the plunger 508 into the bone graft supply line 404.As illustrated in FIGS. 21A-21B, plunger 508 is pushed in the distaldirection, causing graft material to move distally through the bonegraft supply line 404 and into the passage for graft material 392 of theexpandable implant 10, to back-fill the interior cavity 15 of theexpandable implant 10.

In another embodiment of a bone graft supply system, as illustrated inFIGS. 22A-22B, connect cap 502 may be replaced with connect cap 702,which is fitted with a pistol-grip handle 700 to form a bone graft gunfor delivering graft material to the expandable implant 10. The processof attaching and removing connect cap 702 is the same process asattaching and removing connect caps 502 and 504.

After connect cap 702 is connected to handle 550, the distal end ofplunger 708 is inserted into the proximal end of the pistol-grip handle700, as illustrated in FIG. 23. Plunger 708 is designed to work with thepistol-grip handle 700 using a ratcheting advancement mechanism. As thepistol-grip trigger 714 is squeezed towards the handle 700, the trigger714 pivots about pivot point 706 such that movable pawl 710 connected tothe trigger 714 engages ratchet teeth on the plunger 708 and pushes theplunger 708 distally. When the trigger 714 is released, a biasing spring704 moves the trigger 714 back to its original position. As the plunger708 is advanced in the distal direction, the ratchet teeth are pushedthrough a spring-biased fixed pawl 712 that prevents the plunger 708from retracting in the proximal direction, unless the fixed pawl 712 isreleased from engagement with the plunger 708 by pushing the fixed pawl712 against its spring 716. The distal movement of the plunger 708pushes graft material through bone graft supply line 404 and into thepassage for graft material 392 of the expandable implant 10 to fill theinterior cavity 15 of the expandable implant 10. This process isexemplified in FIGS. 24A-24B. It is believed that using a ratchetingmechanism in this manner is preferable over tamping the bone graftmaterial, as tamping may cause jamming of the bone graft material.

The expandable implant 10 can be pre-packed with graft material,back-filled with graft material after implantation, or a combination ofboth. FIG. 25 illustrates one embodiment of a grafting block 800 thatcan be used to help pre-pack the implant 10 with graft material. Aprojection 804 from a base 802 of the grafting block 800 is shaped to beat least partially received within the interior cavity 15 of theexpandable implant 10, as shown in FIGS. 28A-28B, such that theprojection 804 occupies a portion 808 of the interior cavity 15extending from the passage 392, while leaving a remaining open region810 of the interior cavity 15 unoccupied. In that way, that projection804 will prevent graft material packed into the open region 810 of theinterior cavity 15 from filling the portion 808 extending from thepassage 392, which might cause a blockage to the later-inserted graftmaterial when back-filling the expandable implant 10 after insertion.For example, the projection 804 may be configured at one end to a heightthat matches the apex of the ramp 393 inside the expandable implant 10.The remainder of the projection 804 may be configured to a height thatis aligned with the boundary between the implant housing 11 and theexpandable top end plate 13. In that way, any back-filled graft materialadded later will primarily fill the initial portion 808 that was blockedout, as well as the new volume created by the expansion of the implant.

In one embodiment, there is a retaining mechanism 806 that will assistin keeping the expandable implant 10 on the grafting block 800. Theretaining mechanism 806 is adjustable in height, as illustrated in FIGS.26A-26C. Retaining mechanism 806 allows for the expandable implant 10 tobe placed on the projection 804 when the retaining mechanism 806 is inthe raised position. When the retaining mechanism 806 is lowered afterthe expandable implant 10 is placed on the projection 804, the retainingmechanism 806 assists in keeping the expandable implant 10 on thegrafting block 800.

FIGS. 27-28B show an alternative embodiment of the grafting block 800.In the alternative embodiment, the grafting block 800 does not have theretaining mechanism 806. As with other instruments and devices disclosedherein, the use of the grafting block 800 is optional. In one example,when no pre-packing of the graft material is performed (e.g., where thegraft material is entirely supplied via the bone graft supply line 404after the implant 10 has been implanted), the grafting block 800 may notbe used.

The ramp 393 inside the expandable implant 10 is used to guide graftmaterial into the area of the interior cavity 15 that was not pre-packedusing the grafting block 800. The ramp 393 guides new graft materialinto the expanded volume that is created once the expandable implant 10is inserted and expanded.

FIG. 29 illustrates a flexible graft reamer 900 that can be used toclear blockages during backfilling. Graft reamer 900 can also be used tore-establish a grafting channel within passage 392.

As illustrated in FIGS. 30A-30B, the graft reamer 900 fits withindelivery tool 100 while the insertion shaft 500 is connected to theexpandable implant 10. The flexibility of graft reamer 900 allows graftreamer 900 to fit within passage 392 in the expandable implant 10 andaround ramp 393 in the expandable implant 10.

The components of another embodiment of a delivery system areillustrated in FIGS. 32-44. The components of such embodiment areadapted to provide a surgeon with improved viewability of the expandableimplant 10 (both directly and using fluoroscopy), as well as to improvethe speed and efficiency of surgery, so as to minimize the time thattissue is retracted.

In this embodiment, modular parts (including the handle of the deliverytool itself) can be attached to and detached from the insertion shaft ofthe delivery tool between each phase of the procedure. As illustrated inFIG. 32, the modular instruments consist of a handle 2550, an insertionshaft 2500, a rotatable threaded member 2158, a fluid delivery system2400, a bone graft gun 2750, and a bone graft supply line 2404. Themodular parts can be attached to the insertion shaft using a slidinglock mechanism 2535. The sliding lock mechanism 2535 of the handle 2550is illustrated in FIGS. 33A-C, but a similar sliding lock mechanism 2535may be incorporated into the fluid delivery system 2400 and the bonegraft gun 2750 for securely (yet removably) coupling those componentswith the insertion shaft 2500.

As shown in FIGS. 33A-C, the proximal end of the insertion shaft 2500may define a locking mechanism 2534 for securely coupling to the slidinglock mechanism 2535. Specifically, the locking mechanism 2534 is shapedto fit securely within a correspondingly shaped receptacle 2515 in thedistal end of the handle 2550. The locking mechanism 2534 includes arecess 2532 for engaging the sliding lock mechanism 2535, as discussedbelow. The sliding lock mechanism 2535 operates similarly to the slidinglock mechanism 535 of the connect cap 504 illustrated in FIG. 11A. Thatis, the sliding lock mechanism 2535 may be slidable within the distalend of the handle 2550, and it may be biased by one or more springs 2507so that a button 2503 of the sliding lock mechanism 2535 is biased toproject outwardly from an exterior surface of the handle 2550. A stoppin 2509 is received through a slot 2542 in the sliding lock mechanism2535 to constrain the travel of the sliding lock mechanism 2535, suchthat the sliding lock mechanism 2535 is retained within the handle 2550.The sliding lock mechanism 2535 includes a central hole 2537 that isshaped to receive the locking mechanism 2534 of the insertion shaft2500. When handle 2550 is being attached to the proximal end of theinsertion shaft 2500, as illustrated in FIGS. 33A-33C, button 2503 ispressed, causing the springs 2507 to compress, so that the central hole2537 becomes aligned with the locking mechanism 2534. Once thereceptacle 2515 of the handle 2550 receives the locking mechanism 2534of the insertion shaft 2500, button 503 is released, causing the springs2507 to de-compress and lock the locking mechanism 2534 to the slidinglock mechanism 2535. Specifically, when the button 2503 is released, thesliding lock mechanism 2535 slides such that stop pin 2509 slides withinthe slot 2542, and the end 2540 of central opening 2537 slides into therecess 2532 of the locking mechanism 2534. Due to the close fit betweenthe locking mechanism 2534 and the correspondingly shaped receptacle2515 in the distal end of the handle 2550, the engagement of the slidinglock mechanism 2535 with the recess 2532 prevents the handle 2550 frommoving longitudinally and becoming disconnected from the insertion shaft2500 when the button is in its undepressed position. Removal of thehandle 2550 is then done through the reverse process, by pressing thebutton 2503 of the sliding lock mechanism 2535 and lifting the handle2550 off of the insertion shaft 2500.

The insertion of the implant 10 may be accomplished using the componentsillustrated in FIGS. 34A-35B. FIG. 34A shows an exploded view of thehandle 2550, the insertion shaft 2500, the rotatable threaded member2158, and the implant 10. The rotatable threaded member 2158 includes athreaded portion on its distal end, which is inserted into the proximalend of a receptacle 2512 in the insertion shaft 2500. The rotatablethreaded member 2158 then extends out the distal end of the insertionshaft 2500 and screws into the implant 10 to attach the implant 10 tothe insertion shaft 2500, a system which can remain intact throughoutthe procedure. The handle 2550 then attaches to the proximal end of theinsertion shaft 2500, e.g., via sliding lock mechanism 2535, so that thehandle 2550 can be grasped by the surgeon during insertion of theimplant 10 into the intervertebral space. The proximal end of the handle2550 also desirably provides a durable impaction surface to help insertor place expandable implant 10. As shown in FIG. 34B, the handle 2550includes a threaded bore 2536 on its proximal end for receiving a slaphammer, which can help with removal of the implant 10 if necessary.Placement of the implant 10 into the disc space is shown in FIG. 35A.After placement is complete, the handle 2550 can be removed from theinsertion shaft 2500, as shown in FIG. 35B. The insertion shaft 2500 isdesigned to have minimal cross-sectional dimensions, so as to increasevisualization of the implant and its expansion, both directly by thesurgeon as well as via fluoroscopy. The removal of the handle 2550enhances visibility even further.

After removing the handle 2550 from the insertion shaft 2500, the fluiddelivery system 2400 may be attached to the insertion shaft 2500 toexpand the implant 10. An exploded view of the fluid delivery system2400 is illustrated in FIG. 36. The fluid delivery system 2400 includesa fluid delivery cannula 2154, a reservoir 2518, a plunger 2506, and aconnect cap 2502. The connect cap 2502 desirably includes a sliding lockmechanism 2535 for attaching the fluid delivery system 2400 to thelocking mechanism 2534 at the proximal end of the insertion shaft 2500,in the same manner shown in FIGS. 33A-C. As shown in FIGS. 37A-37B, thedistal end of the fluid delivery cannula 2154 may be inserted into areceptacle 2514 on the proximal end of the insertion shaft 2500. Afterthe fluid delivery cannula 2154 is seated in the insertion shaft 2500,the outlet 2152 for delivering pressurized fluid will be located at thedistal end of the insertion shaft 2500, where it can fluidly communicatewith the inlet of a pressure channel on the proximal end of theexpandable implant 10. Specifically, in the same manner shown in FIGS.15A and 7B, the outlet 2152 of this embodiment may likewise project fromthe distal end of the insertion shaft 2500, such that it is partiallyreceived within the inlet of the expandable implant, where it can form asealing connection by engaging an o-ring positioned within the pressurechannel of the implant 10. In the present embodiment, the reservoir 2518may be angled with respect to the fluid delivery cannula 2154, whichpreferably positions the reservoir 2518 out of the line of site of thesurgeon and/or the fluoroscope to the implant. Desirably, suchpositioning improves visibility for viewing the implant 10, as well asrelocating a user's hands outside the radiation area of the fluoroscope.Preferably, the reservoir 2518 may be angled at 90 degrees with respectto the fluid delivery cannula 2154, although other angles to positionthe reservoir 2518 away from the viewing area could also be used.

The reservoir 2518 may receive the threaded plunger 2506 to pressurizethe system. The plunger 2506 may be engaged by a plunger engagementmechanism 2008, as shown in FIGS. 38A-C. Like the selector mechanism1004 of FIGS. 31A-31E, the plunger engagement mechanism 2008 of theembodiment of FIGS. 38A-C may be designed to allow two modes of travelby the plunger 2506. The plunger engagement mechanism 2008 is slidablewithin a proximal portion of the reservoir 2518, and it may be biased byone or more springs 2025 so that a button 2003 of plunger engagementmechanism 2008 is biased to project outwardly from an exterior surfaceof the reservoir 2518. A stop pin 2009 is received through a slot 2042in the plunger engagement mechanism 2008 to constrain the travel of theplunger engagement mechanism 2008, such that the plunger engagementmechanism 2008 is retained within the reservoir 2518. The plungerengagement mechanism 2008 includes a central hole 2037 that is shaped toreceive the plunger 2506 through it. At least one side of the holeincludes a threaded portion 2016 structured to engage the threads of theplunger 2506. When the plunger 2506 is inserted into the reservoir 2518,button 2003 is pressed, causing the spring 2025 to compress, so thatplunger 2506 can freely slide though the central hole 2037. Thus,holding the button 2003 in a depressed state allows for one of the twomodes of travel by the plunger 2506, in which the threaded portion 2016of the plunger engagement mechanism 2008 is disengaged from the threadsof the plunger 2506, so that the plunger can travel along the reservoir2518 by sliding the plunger 2506 linearly through the opening 2037 inthe plunger engagement mechanism 2008. By releasing the button 2003, thespring 2025 will de-compress and cause the threaded portion 2016 of theplunger engagement mechanism 2008 to move into engagement with thethreads of the plunger 2506, which activates the other mode of travel bythe plunger 2506. That is, due to the threaded engagement between thethreads of the plunger 2506 and the threaded portion 2016 of the plungerengagement mechanism 2008, the plunger can travel along the reservoir2518 by rotation about the longitudinal axis of the plunger.

As with the embodiment of the selector mechanism 1004 of FIGS. 31A-31E,the two modes of travel of the plunger 2506 through the plungerengagement mechanism 2008 may desirably permit the plunger 2506 toadvance the hydraulic fluid into the implant in the rotational, threadedengagement mode, and then the plunger 2506 can be quickly released bydepressing the button 2003 and pulling the plunger 2506 in the proximaldirection. The two states of engagement between the plunger engagementmechanism 2008 and the plunger 2506 may also give the surgeon a choicebetween two modes for delivery of the hydraulic fluid into the implant.That is, the surgeon may use the threaded advancement mode if a slowerand more controlled advancement is appropriate, and/or if it isdesirable to employ the mechanical advantage provided by the screw driveto amplify the input force. The surgeon may also choose to use thesliding, non-threaded mode if more rapid advancement of the plunger isdesirable. The sliding, non-threaded mode may also desirably allow theplunger 2506 to be initially positioned into or removed from thereservoir 2518 relatively quickly, by eliminating the need to threadedlyadvance or retract the plunger 2506 the entire distance to the desiredposition.

After the implant 10 has been expanded under the influence of thepressurized fluid, the implant 10 may be repositioned (if desired) byunlocking the expansion mechanism, such as by pressing distally on theunlocking tether 212 a. In one embodiment of the fluid delivery system2400, the fluid delivery cannula 2154 may be advanceable distallyrelative to the reservoir 2518, so as to push on the unlocking tether212 a within the expandable implant 10, in the same manner asillustrated in FIG. 15D. In another embodiment, the fluid deliverysystem 2400 may be removed from the insertion shaft 2500, and then atube or other rigid, elongate component may be inserted into the samereceptacle 2514 at the proximal end of the insertion shaft, so as totravel through the insertion shaft 2500 and push the unlocking tether212 a of the implant 10.

Once the implant is placed and expanded, the fluid delivery system 2400may be removed from the insertion shaft 2500, as shown in FIGS. 39A-B.The bone graft supply system may then be attached to the insertion shaft2500 to fill the expanded implant 10 with bone graft material. The bonegraft supply system may include a bone graft gun 2750 having a connectcap 2702 and a bone graft supply line 2404. The steps of using the bonegraft gun 2750 are shown in FIGS. 40A-42C. Specifically, the bone graftsupply line 2404 may first be connected to the bone graft gun 2750, asshown in FIGS. 40A-B. The proximal portion of the bone graft supply line2404 includes a recess 2519 around at least a portion of its outerperiphery. That recess 2519 is shaped to engage the sliding lockmechanism 2535 of the connect cap 2702 of the bone graft gun 2750 inmuch the same manner that the recess 2532 on the insertion shaft 2500engages the end 2540 of the central opening 2537 of the sliding lockmechanism 2535 in order to secure the insertion shaft 2500 to the handle2550. Thus, both the bone graft supply line 2404 and the insertion shaft2500 can be secured to the connect cap 2702 of the bone graft gun 2750via the sliding lock mechanism 2535. In particular, with regard to thebone graft supply line 2404, the proximal portion of the bone graftsupply line 2404 is inserted into a corresponding receptacle 2526 on theconnect cap 2702 of the bone graft gun 2750 while the button 2503 of thesliding lock mechanism 2535 is depressed. The depressing of the button2503 causes the central opening 2537 of the sliding lock mechanism 2535to be positioned such that the proximal portion of the bone graft supplyline 2404 can be received through the central opening 2537. Then, thebone graft supply line 2404 can be secured to the bone graft gun 2740 byreleasing the button 2503, which results in the biasing of the slidinglock mechanism 2535 to a shifted position, in which a portion of theperiphery of the central opening 2537 is received within the recess 2519of the bone graft supply line 2404, as shown in FIG. 41B.

The bone graft gun 2750 with attached bone graft supply line 2404 isthen connected to the insertion shaft 2500, as shown in FIGS. 42A-B.Specifically, the distal end of the bone graft supply line 2404 isplaced within an opening 2516 at the distal end of the insertion shaft2500 (see FIGS. 34B and 39A), such that the bone graft supply line 2404is positioned alongside the insertion shaft 2500, where it may bepartially received in and supported by a groove or channel 2517extending along the insertion shaft 2500 (see FIG. 34B). The connect cap2702 of the bone graft supply gun 2750 is also connected to the lockingmechanism 2534 at the proximal end of the insertion shaft 2500 via asliding lock mechanism 2535 like that of handle 2550. The distal end ofplunger 2508 is then inserted into the proximal end of the bone graftsupply line 2404. Plunger 2508 is designed to work with the bone graftgun 2750 using a pistol-grip trigger 2714 and a ratcheting advancementmechanism like that shown in FIGS. 24A-B.

When all phases of the surgery are complete, the insertion shaft 2500can be removed from the implant 10 by unthreading the rotatable threadedmember 2158.

In alternative embodiments, as illustrated in FIGS. 43-44, the insertionshaft may include bend angles within one or more planes. For example,for an L4/L5 lateral approach (e.g., in a trans-psoas oranterior-to-psoas (“ATP”) approach), an insertion shaft 3500 may beprovided having a single bend 3513 in a cephalad direction within thefrontal or coronal plane. As shown in FIG. 43, such bend 3515 may allowthe insertion shaft 3500 to avoid the iliac crest IC. A bend in theanterior direction within the horizontal or transverse plane mayadditionally or alternatively be provided. For example, for an ATPapproach, an insertion shaft 4500 may be provided having a compound bend4513, consisting of a cephalad bend like that shown in FIG. 43, as wellas a bend in the anterior direction within the horizontal or transverseplane, as shown in FIG. 44. All of such bends are preferably locatedapproximately 40 millimeters from the distal end of the insertion shaft3500, and the bends preferably have an angle between 15 and 30 degrees.

One or more components of the delivery tool 100, such as handle 550, aredesirably made of radiolucent material, such that they do not impairvisualization of the implant 10 (e.g., by fluoroscopy) while it is beingimplanted and further manipulated. The components of the connect caps,including the sliding lock mechanisms, may be fabricated from a plasticto reduce blockage of imaging, while the fluid delivery cannula 2154 andthe reservoir 2518 may be fabricated from a metal for strength anddurability.

Particularly in the case of an insertion shaft 3500 having an angledbend, such as those shown in FIGS. 43-44, the rotatable threaded member158 may be made of a flexible material or it may have a flexible portioncorresponding to the position of the bend. The fluid delivery cannula154 may also be fabricated from a flexible material, such as nitinol, totravel through the bent insertion shaft 3500. The bone graft supply line404 may also be fabricated from a flexible material, or a non-flexiblematerial having a bend that matches that of the insertion shaft 3500.

To assist the Patent Office and anyone else considering this application(or any patent issuing thereon) in interpreting the accompanying claims,Applicant notes that none of the claim language is intended to invokethe provisions of 35 U.S.C. § 112(f) unless the words “means for” or“step for” are explicitly used.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A method for packing an implant with graft material, comprising:providing the implant having an internal cavity; selectively packing afirst region of the internal cavity with graft material, wherein whenpacking the first region with graft material a second region of theinternal cavity remains absent of graft material; inserting theselectively packed implant between first and second vertebral bodies;and subsequent to the inserting step, supplying additional bone graftmaterial into the second region of the internal cavity.
 2. The method ofclaim 1, further comprising, prior to the selectively packing step,receiving the implant, by a block having a projection, wherein theprojection is received through an opening into the internal cavity suchthat the projection occupies the second region of the internal cavity.3. The method of claim 2, wherein the projection has a varying heightalong a longitudinal axis of the projection.
 4. The method of claim 3,wherein a first portion of the varying height of the projectioncorresponds to a height of a ramped port of the implant when theprojection is received in the internal cavity.
 5. The method of claim 4,wherein a second portion of the varying height of the projectioncorresponds to a boundary between a housing and a top plate of theimplant, the top plate being movable away from the housing so as toexpand the implant.
 6. The method of claim 4, wherein the ramped portguides the additional bone graft material into the second region.
 7. Themethod of claim 2, further comprising securing the implant on the blockvia an adjustable retaining mechanism.
 8. The method of claim 1, whereinwhen supplying the additional bone graft material into the secondregion, the additional bone graft material is guided into the secondregion by a ramped port of the implant.
 9. The method of claim 1,further comprising: subsequent to the inserting step, expanding theimplant such that the internal cavity expands to include a third region.10. The method of claim 9, further comprising supplying the additionalbone graft material into the third region of the internal cavity. 11.The method of claim 1, wherein inserting the selectively packed implantfurther includes securing a distal end of an elongated tool to aproximal end of the implant.
 12. The method of claim 11, whereinsupplying the additional bone graft material into the second region ofthe internal cavity comprises: inserting a bone graft supply line withina receptacle of the elongated tool; inserting a plunger into the bonegraft supply line; and advancing the plunger distally through the bonegraft supply line.
 13. The method of claim 12, wherein advancing theplunger distally through the bone graft supply line includes squeezing atrigger of a pistol grip handle secured to a proximal end of theelongated tool to drive the advancement of the plunger in a distaldirection.
 14. The method of claim 12, wherein the elongated toolincludes an angled bend along its length, and wherein the bone graftsupply line has a bend corresponding to the angled bend of the elongatedtool when the bone graft supply line is inserted within the receptacle.15. The method of claim 11, further comprising inserting a reamerthrough a receptacle of the elongated tool and into the internal cavityof the implant to clear a blockage.
 16. The method of claim 1, furthercomprising inserting a reamer through a port of the implant and into theinternal cavity to clear a blockage.
 17. The method of claim 16, whereinthe reamer is flexible such that the reamer can deflect along a rampdefined within the implant.
 18. A block for supporting an intervertebralimplant while packing an interior cavity of the implant with graftmaterial, comprising: a base; and a projection extending from the base,the projection being sized to be received through a first opening in theimplant such that the projection is positioned at least partially withinthe interior cavity of the implant.
 19. An spinal implant system,comprising: the block of claim 18; and the intervertebral implant,wherein the implant includes a second opening on an opposite side of theimplant from the first opening, and, wherein, when the implant issupported on the block with the projection received through the firstopening in the implant, the second opening is oriented upwardly so as toreceive a supply of graft material into the interior cavity through thesecond opening.
 20. The spinal implant system of claim 19, wherein theprojection of the block is configured to closely fit within the interiorcavity of the implant such that graft material positioned within theinterior cavity is prevented from flowing downwardly past an uppersurface of the projection into a portion of the interior cavity occupiedby the projection.